The most common Doulton mark is circular with the central four interlicking D symbols that continued in later marks. A similar device with a crown above, was used from 1886 to mark the appointment of Doulton as potters to His Royal Highness the Prince of Wales.

What do Royal Doulton numbers mean?

Code numbers were printed on the base of Royal Doulton produced between 1928 until 1954. These numbers appear next to the right of the crown. The rule of thumb with these numbers is to add 1927. For example, if your inked number is 1 the year your item was manufactured in 1928.